There are two general ways to get your green card. First, you can apply through consular processing while you are living in the country of your nationality. Secondly, you can apply to be a permanent resident from within the US, while you are legally in the US. This second method is known as adjustment of status. There are many benefits to getting an adjustment of status rather than consular processing if you need your green card. By applying through adjustment of status, for example, you can avoid long waits to enter the US. As well, you can apply for employment authorization immediately, while your adjustment of status request is still pending in most cases, and you do not have to provide the same police certification as you would with consular processing. Finally, with adjustment of status you can appeal a negative decision.
There are many situations in which you will need to apply for adjustment of status. If you have entered the United States on a K visa and have married a US citizen, for example, you will generally need to apply for adjustment of status in order to apply for a green card once you are married. If you have entered the US on an employment visa and are getting sponsored by your employer for full green card status, you will eventually have to apply for adjustment of status as well.
In order to apply for adjustment of status, you will need to file form I-485 (Application to Register Permanent Residence or Adjust Status) with the USCIS. Once your form is approved, you will eventually get an adjustment of status interview notice. This will list the time and place of the interview and will list the documents you need to bring to the interview. Depending on your application, you may need biographic documents, past and current passports, an original I-94 card, a marriage certificate, birth certificates, divorce decrees, and other documentation. Make sure that you bring all the documentation you are requested to bring. If your interview is successful, your adjustment of status will generally be approved.